Synchronizer Neutral Positioning via Clearance Compensation
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Solution Overview
Problem
The existing synchronizer technology faces issues with accurate neutral positioning, leading to potential burning damage, friction, and drag due to improper spacing of the key unit between rings, which affects fuel efficiency.
Innovation Solution
A neutral controlling method for the synchronizer that involves a series of precise movements by the shift mechanism to accurately position the sleeve at the neutral position, accounting for invalid strokes caused by clearances, ensuring the key unit is centered between the rings, thereby preventing damage and improving fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If clearances are provided between the finger and lug, and between the shift fork and groove part to enable smooth operation, then ease of operation is improved, but positioning precision deteriorates causing the sleeve to be biased from the neutral position
Solution Approach 1:
The control method performs preliminary actions by intentionally moving the sleeve beyond the theoretical neutral position by a predetermined distance that compensates for the invalid stroke caused by clearances. This preliminary over-travel ensures that after the clearances are taken up during operation, the sleeve ends up at the correct neutral position, thus resolving the positioning inaccuracy caused by the clearances needed for smooth operation.
2Ease of operation
If the sleeve is not accurately positioned at the neutral position, then ease of operation is maintained with clearances, but harmful factors increase due to burning damage, friction, and drag of the rings
Solution Approach 1:
The control method uses feedback by calculating the actual neutral position based on the known invalid stroke distance caused by clearances. The control unit adjusts the stopping position of the sleeve by adding the invalid stroke compensation to the theoretical neutral position, ensuring that the key unit is correctly positioned between the rings even when clearances exist in the mechanism, thereby preventing burning damage, friction, and drag.
3Device complexity
If the key unit is not properly spaced from the rings due to positioning errors, then device complexity is reduced with simple clearances, but reliability deteriorates due to potential burning damage and friction
Solution Approach 1:
The control method changes the positional parameter of the sleeve by introducing an invalid stroke compensation distance. Instead of relying on mechanical precision alone, the control system adjusts the movement parameter of the sleeve to account for the clearance-induced invalid stroke, ensuring reliable spacing between the key unit and rings while maintaining the simplicity of the mechanical clearance design.
Data Source
AI summary
A neutral controlling method of a synchronizer includes: a primary moving step of moving a sleeve in one direction by a shift mechanism until the sleeve contacts a first stopper of a first clutch gear; a secondary moving step of moving the sleeve in the other direction by the shift mechanism until the sleeve contacts a second stopper of a second clutch gear; and a neutral position moving step of moving the sleeve to a neutral position between the two clutch gears. In particular, in the neutral position moving step, the sleeve moves in one direction as much as a half of a stroke and the stroke of the sleeve is a summed value of a straight distance between the first stopper and the second stopper with an invalid stroke formed due to a clearance between parts of the shift mechanism and the synchronizer.